Effect of pre- and post-emergence herbicides on weed control and productivity of soybean (Glycine max)

A field experiment was conducted during the rainy seasons of 2000 and 2001 on Vertisol, to study the effect of different pre- and post-emergence herbicides on 'JS 335' soybean [Glycine max (L.) Merr.]. Among the tested herbicides, the highest seed yield was recorded with combi product of imazamox + imazethapyr @ 75 g/ha PoE, i.e. 1,622 kg/ha, and it was significantly on a par with 2 hand-weedings (1,710 kg/ha). The highest weed-control efficiency and lowest weed biomass were recorded with 2 hand-weedings, followed by application of imazamox + imazethapyr @ 75 g/ha PoE and quizalofop ethyl @ 50 g/ha PoE. Among the pre-emergence herbicides, S-metolachlor @ 750 g/ha performed better than application of alachlor @ 2 kg/ha and lower dose of S-metolachlor @ 500 g/ha.